i STRUCTURAL PERFORMANCE OF ASPHALT BLOCKS PAVEMENT AS RELATED TO THICKNESS, BINDER TYPES, AND JOINT WIDTH AHMED SALAMA ELTWATI A thesis submitted in fulfilment of the requirements for the award of the degree of Doctor of Philosophy (Civil Engineering) Faculty of Civil Engineering Universiti Teknologi Malaysia MAY2015
iii Dedicated to Allah S.W.T, my beloved Mother and Father Thanks for your support and love.
iv ACKNOWLEDGEMENT First and foremost, I would like to thank Allah S.W.T for blessing me to complete this important step in my life. Special thanks and my sincere appreciation to my main supervisor Prof. Dr. Hasanan Bin Md. Nor for encouragement guidance, critics and friendship.without his continued support and interest, this thesis would not have been the same as presented here. I am also indebtedto the highway laboratory technicians and my fellow postgraduate studentsat Universiti Teknologi Malaysia (UTM), who showed their concern andsupport all the way. I would like thank in particular Dr. Azman Bin Mohamed whose views and tips were useful indeed.finally, I am grateful to all my family members.
v ABSTRACT Asphalt block pavement is an innovative alternative to asphalt pavements. This study investigated the performance of asphalt paving blocks with a number of variables: block thickness, bitumen types and joint width between blocks. The effect of dynamic and static loads and their transfer from one block to another on the behaviour of asphalt block pavements were studied. Asphalt blocks were laid on sand bedding, but direct laying on a base course was also investigated. The experiments conducted in the laboratory were push-in test, pull-out test, and accelerated trafficking test. Two types of bitumen were used as binder to produce asphalt blocks: normal bitumen (60/70) and modified bitumen (PG 76) and different block thicknesses: 70 mm, 80 mm, and 90 mm. Asphalt blocks were laid in stretcher bond with various joint widths: no joint spacing, 2 mm, and 3 mm. The instruments of the push-in test and pull-out test were constructed within a steel box of 1.0 metre square; the push-in vertical load was increased from 0 to 30 kn on the samples of asphalt blocks. The accelerated trafficking loading test was conducted in a steel platform of 1.0 m 5.0 m, the loaded wheel was moved over the pavement model and the deflection was taken at specific intervals. The results indicate that asphalt blocks have a great performance after being exposed to static load and dynamic load. The study shows that placing asphalt blocks directly on the base course resulted in uneven surface; therefore the bedding sand layer is a necessary component in the structure of asphalt block pavements. From the statistical results, the thickness of the block has insignificant impact on the structural performance. However, there is a trend that a change in block thickness from 70 to 90 mm decreases the deflection and displacement of asphalt block pavement which could be due to a greater frictional area and load transfer, thus increase the response of the pavement. The results also show the type of bitumen used in this study has insignificant impact on the structural performance. However, it has an impact on the compressive strength and density of the block. The finding reveals that placing blocks with no joint spacing is found to yield the best performance.
vi ABSTRAK Turapan blok asfalt adalah inovatif yang alternatif kepada turapan asfalt. Kajian ini dijalankan untuk mengkaji prestasi struktur turapan blok asfalt dengan beberapa perubahan seperti ketebalan blok, jenis-jenisbitumen dan jarak antara blok yang digunakan. Kesan dinamik dan beban statik dan pemindahan dari satu blok ke blok lain pada prestasi blok turapan asfalt turut dikaji. Blok asfalt disusun atas lapisan pasir pengalas, tetapi turapan terus ke atas fondasi jalan juga dikaji. Eksperimen yang dijalankan adalah ujian bebanan tekan masuk, ujian bebanan tarik keluar, dan ujian lalu lintas dipercepatkan. Dua jenis bitumen digunakan untuk menghasilkan blokasfalt: bitumen biasa (60/70) dan bitumen diubahsuai (PG 76) dan ketebalan blok yang berbeza iaitu 70 mm, 80 mm dan 90 mm. Blok asfalt diletakkan bersama dalam corak ikatan usungan dengan tiada jarak di antara blok, 2 mm, dan 3 mm. Ujian bebanan tekan masuk dan ujian bebanan tarik keluar dilakukan dalam kotak keluli 1.0 meter persegi, dengan tekanan beban tegak ditingkat kandaripada sifar kepada 30 kn atas sampel blok asfalt. Ujian lalu lintas dipercepat kan dilakukan dalam platform keluli 1.0 m 5.0 m di mana defleksi diambil secara khusus bila tayar-tayar melalui model turapan tersebut. Selepas didedah kepada beban statik dan dinamik, kajian telah menunjukkan bahawa blok asphalt mempunyai prestasi yang baik. Kajian tersebut menunjukkan bahawa blok asfalt yang diletakkan di atas lapisan fondasi menyebabkan permukaan yang tidak sekata. Oleh itu, lapisan pasir pengalas adalah satu komponen yang penting dalam struktur turapan blok asfalt. Dari keputusan statistik, ketebalan blok tidak memberikan kesan pada struktur prestasi. Walau bagaimanapun, keputusan ada menunjukkan kecenderungan di mana perubahan ketebalan blok dari 70 mm ke 90 mm menurunkan defleksi dan anjakan turapan blok asfalt. Blok tebal mengakibatkan geseran yang lebih luas dan perpindahan beban yang lebih besar, seterusnya meningkatkan tindak balas turapan. Pengujian tersebut menunjukkan bahawa jenis bitumen yang digunakan dalam kajian ini tidak banyak menghasilkan kesan dalam struktur prestasi.walau bagaimanapun, ia mempunyai kesan ke atas kekuatan mampatan dan ketumpatan blok. Keputusan ujikaji menunjukkan tanpa menjarakkan blok asfalt antara satu sama lain dapat menghasilkan kesan yang paling baik.